A Silver color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a shield blazoned as follows: Azure, on a fess Argent (White) a prickly pear cactus Proper between a sheathed Roman sword palewise and a fleur-de-lis of the first, on a wreath a demi-lion rampant holding in dexter paw a laurel branch all of the second (Silver). Attached below and to the sides of the shield a Silver bipartite scroll inscribed "WIDE AWAKE WIDE AWAKE" in Blue letters.
The shield is blue for Infantry, the original unit designation. The white fess charged with the Roman sword, cactus, and fleur-de-lis represents the Spanish-American War, Mexican Border, and World War I service, respectively.
The distinctive unit insignia was approved for the 151st Infantry Regiment on 5 June 1935.